What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
Acft exper a rough running engine, made an emergency landing at old dutton arpt. Ran off end of rwy. (.4)in level flight at 2,000 feet, the engine began running rough with an associated vibration. The CFI took control of the airplane and the vibration became stronger. After shutting down the engine, the CFI attempted to land on an abandoned runway. The airplane impacted trees approximately 100 feet beyond the departure end of the abandoned runway. Examination of the engine logbooks and discussions with the operator disclosed that the engine was 362 hours beyond time between overhaul (tbo) and automotive fuel was utilized without a supplemental type certificate. Disassembly of the engine revealed the number two cylinder's exhaust valve was fractured and the cylinder was cracked. An examination of the fractured exhaust valve by the materials laboratory division of the national transportation safety board revealed that the 'shank area immediately adjacent to the fracture was reduced in size, and the fracture features were indicative of bending overstress separation with no indications of pre-existing cracking.' (-23) engine failure. Exhaust valve stem elongated then failed near head. Catastrophic damage to piston and cylinder.
As the FAA filed it
ACFT EXPER A ROUGH RUNNING ENGINE, MADE AN EMERGENCY LANDING AT OLD DUTTON ARPT. RAN OFF END OF RWY. (.4)IN LEVEL FLIGHT AT 2,000 FEET, THE ENGINE BEGAN RUNNING ROUGH WITH AN ASSOCIATED VIBRATION. THE CFI TOOK CONTROL OF THE AIRPLANE AND THE VIBRATION BECAME STRONGER. AFTER SHUTTING DOWN THE ENGINE, THE CFI ATTEMPTED TO LAND ON AN ABANDONED RUNWAY. THE AIRPLANE IMPACTED TREES APPROXIMATELY 100 FEET BEYOND THE DEPARTURE END OF THE ABANDONED RUNWAY. EXAMINATION OF THE ENGINE LOGBOOKS AND DISCUSSIONS WITH THE OPERATOR DISCLOSED THAT THE ENGINE WAS 362 HOURS BEYOND TIME BETWEEN OVERHAUL (TBO) AND AUTOMOTIVE FUEL WAS UTILIZED WITHOUT A SUPPLEMENTAL TYPE CERTIFICATE. DISASSEMBLY OF THE ENGINE REVEALED THE NUMBER TWO CYLINDER'S EXHAUST VALVE WAS FRACTURED AND THE CYLINDER WAS CRACKED. AN EXAMINATION OF THE FRACTURED EXHAUST VALVE BY THE MATERIALS LABORATORY DIVISION OF THE NATIONAL TRANSPORTATION SAFETY BOARD REVEALED THAT THE 'SHANK AREA IMMEDIATELY ADJACENT TO THE FRACTURE WAS REDUCED IN SIZE, AND THE FRACTURE FEATURES WERE INDICATIVE OF BENDING OVERSTRESS SEPARATION WITH NO INDICATIONS OF PRE-EXISTING CRACKING.' (-23) ENGINE FAILURE. EXHAUST VALVE STEM ELONGATED THEN FAILED NEAR HEAD. CATASTROPHIC DAMAGE TO PISTON AND CYLINDER.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.